Digital-controlled vector signal modulator

Abstract

A vector modulator includes a quadrature component generator, configured to generate an input in-phase signal and an input quadrature signal according to an input radio frequency (RF) signal; a switching circuit, receiving a plurality of bits, comprising a plurality of switches controlled by the plurality of bits, configured to generate an output in-phase signal and an output quadrature signal according to the plurality of bits, where the output in-phase signal and the output quadrature signal are related to input in-phase signal and the input quadrature signal; and a combining module, configured to generate an output RF signal according to the output in-phase signal and the output quadrature signal.

What is claimed is: 
     
       1. A vector modulator, comprising:
 a quadrature component generator, configured to generate an input in-phase signal and an input quadrature signal according to an input radio frequency (RF) signal; 
 a switching circuit, receiving a plurality of bits, comprising a plurality of switches controlled by the plurality of bits, configured to generate an output in-phase signal and an output quadrature signal according to the plurality of bits, where the output in-phase signal and the output quadrature signal are related to input in-phase signal and the input quadrature signal; and 
 a combining module, configured to generate an output RF signal according to the output in-phase signal and the output quadrature signal. 
 
     
     
       2. The vector modulator of  claim 1 , wherein the switching circuit comprises:
 a switching input terminal, coupled to the quadrature component generator; 
 a switching output terminal, coupled to the combining module; 
 a plurality of conducting switches, coupled between the switching input terminal and the switching output terminal, controlled by a plurality of conducting bits within the plurality of bits; and 
 a plurality of diverting switches, coupled to the switching input terminal and receiving a voltage, controlled by a plurality of diverting bits within the plurality of bits, wherein the plurality of diverting bits are complements of the plurality of conducting bits. 
 
     
     
       3. The vector modulator of  claim 1 , further comprising an in-phase amplifier, coupled between the quadrature component generator and the switching circuit, configured to receive the input in-phase signal and output an intermediate in-phase signal; and
 a quadrature amplifier, coupled between the quadrature component generator and the switching circuit, configured to receive the input quadrature signal and output an intermediate quadrature signal. 
 
     
     
       4. The vector modulator of  claim 3 , wherein
 the input in-phase signal comprises a first input in-phase signal and a second input in-phase signal; 
 the input quadrature signal comprises a first input quadrature signal and a second input quadrature signal; 
 the in-phase amplifier comprises a first in-phase output terminal and a second in-phase output terminal; 
 the quadrature amplifier comprises a first quadrature output terminal and a second quadrature output terminal; 
 the intermediate in-phase signal comprises a first intermediate in-phase signal and a negative intermediate in-phase signal; 
 the intermediate quadrature signal comprises a first intermediate quadrature signal and a negative intermediate quadrature signal; 
 the output in-phase signal comprises a first output in-phase signal and a second output in-phase signal; 
 the output quadrature signal comprises a first output quadrature signal and a second output quadrature signal; 
 the output RF signal comprises a first output RF signal and a second output RF signal; and 
 the combining module comprises:
 a first combining element, configured to generate the first output RF signal according to the first output in-phase signal and the first output quadrature signal; and 
 a second combining element, configured to generate the second output RF signal according to the second output in-phase signal and the second output quadrature signal. 
 
 
     
     
       5. The vector modulator of  claim 4 , wherein the switching circuit comprises:
 a first in-phase switching sub-circuit, comprising:
 a first in-phase switching input terminal, coupled to the first in-phase output terminal of the in-phase amplifier; 
 a second in-phase switching input terminal, coupled to the second in-phase output terminal of the in-phase amplifier; 
 a first in-phase switching output terminal; 
 a second in-phase switching output terminal; 
 a plurality of first in-phase conducting switches, coupled between the first in-phase switching input terminal and the first in-phase switching output terminal, controlled by a plurality of in-phase conducting bits within the plurality of bits; and 
 a plurality of second in-phase conducting switches, coupled between the second in-phase switching input terminal and the second in-phase switching output terminal, controlled by the plurality of in-phase conducting bits within the plurality of bits; 
 a plurality of first in-phase diverting switches, coupled to the first in-phase switching input terminal and receiving a voltage, controlled by a plurality of in-phase diverting bits within the plurality of bits, wherein the plurality of in-phase diverting bits are complements of the plurality of in-phase conducting bits; and 
 a plurality of second in-phase diverting switches, coupled to the second in-phase switching input terminal and receiving the voltage, controlled by the plurality of in-phase diverting bits; and 
 
 a first quadrature switching sub-circuit, comprising:
 a first quadrature switching input terminal, coupled to the first quadrature output terminal of the quadrature amplifier; 
 a second quadrature switching input terminal, coupled to the second quadrature output terminal of the quadrature amplifier; 
 a first quadrature switching output terminal; 
 a second quadrature switching output terminal; 
 a plurality of first quadrature conducting switches, coupled between the first quadrature switching input terminal and the first quadrature switching output terminal, controlled by a plurality of quadrature conducting bits within the plurality of bits; 
 a plurality of second quadrature conducting switches, coupled between the second quadrature switching input terminal and the second quadrature switching output terminal, controlled by the plurality of quadrature conducting bits within the plurality of bits; 
 a plurality of first quadrature diverting switches, coupled to the first quadrature switching input terminal and receiving the voltage, controlled by a plurality of quadrature diverting bits within the plurality of bits, wherein the plurality of quadrature diverting bits are complements of the plurality of first quadrature conducting bits; and 
 a plurality of second quadrature diverting switches, coupled to the second quadrature switching input terminal and receiving the voltage, controlled by the plurality of quadrature diverting bits. 
 
 
     
     
       6. The vector modulator of  claim 5 , wherein the switching circuit comprises:
 a second in-phase switching sub-circuit, comprising:
 a first in-phase switching input terminal, coupled to the second in-phase output terminal of the in-phase amplifier; 
 a second in-phase switching input terminal, coupled to the first in-phase output terminal of the in-phase amplifier; 
 a first in-phase switching output terminal; 
 a second in-phase switching output terminal; 
 a plurality of first in-phase conducting switches, coupled between the first in-phase switching input terminal and the first in-phase switching output terminal, controlled by a plurality of in-phase conducting bits within the plurality of bits; and 
 a plurality of second in-phase conducting switches, coupled between the second in-phase switching input terminal and the second in-phase switching output terminal, controlled by the plurality of in-phase conducting bits within the plurality of bits; 
 a plurality of first in-phase diverting switches, coupled to the first in-phase switching input terminal and receiving the voltage, controlled by a plurality of in-phase diverting bits within the plurality of bits, wherein the plurality of first in-phase diverting bits are complements of the plurality of in-phase conducting bits; and 
 a plurality of second in-phase diverting switches, coupled to the second in-phase switching input terminal and receiving the voltage, controlled by the plurality of in-phase diverting bits; and 
 
 a second quadrature switching sub-circuit, comprising:
 a first quadrature switching input terminal, coupled to the second quadrature output terminal of the quadrature amplifier; 
 a second quadrature switching input terminal, coupled to the first quadrature output terminal of the quadrature amplifier; 
 a first quadrature switching output terminal; 
 a second quadrature switching output terminal; 
 a plurality of first quadrature conducting switches, coupled between the first quadrature switching input terminal and the first quadrature switching output terminal, controlled by a plurality of quadrature conducting bits within the plurality of bits; 
 a plurality of second quadrature conducting switches, coupled between the second quadrature switching input terminal and the second quadrature switching output terminal, controlled by the plurality of quadrature conducting bits within the plurality of bits; 
 a plurality of first quadrature diverting switches, coupled to the first quadrature switching input terminal and receiving the voltage, controlled by a plurality of quadrature diverting bits within the plurality of bits, wherein the plurality of first quadrature diverting bits are complements of the plurality of first quadrature conducting bits; and 
 a plurality of second quadrature diverting switches, coupled to the second quadrature switching input terminal and receiving the voltage, controlled by the plurality of quadrature diverting bits.